Iridescent cloud

On my way home from work I spotted this faint  iridescent cloud through the sunroof of my truck.  Anyhow long story short I had to get a shot if it.  What is the big blurry thing at the bottom of the frame you ask?  Well, that is a fence post I used to block out the glare of the sun so I could get the shot otherwise the entire frame would have been blown out.